Night Shift Damages Genes: Body's Natural Rhythm Disrupted

When we don't get enough sleep, we get cranky, we can't think straight, and worse yet, it disrupts the body's natural rhythm. According to a recent study by researchers from the University of Surrey, this means that those catching up on missed zzz's during the daytime may actually be at a greater risk for certain chronic diseases due to an alteration of the human transcriptome.

For the study, a research team placed 22 participants on a 28-hour day controlled sleep cycle that did not have a light-dark cycle. This caused their sleep-wake cycle to be delayed by up to four hours every day until they were running 12 hours out of sync due to their "brain clock."

"This research may help us to understand the negative health outcomes associated with shift work, jet lag and other conditions in which the rhythms of our genes are disrupted," said Senior author Professor Derk-Jan Dijk, from the Sleep Research Centre at the University of Surrey, via a news release. "The results also imply that sleep-wake schedules can be used to influence rhythmicity in many biological processes, which may be very relevant for conditions in which our body clocks are altered, such as in [aging]."

During the middle of the day, the participants started to experience the beginning of their sleep cycle. The researchers then collected blood samples from study participants in order to determine the rhythms of gene expression. According to the study, researchers observed a "six-fold" decrease in genes that displayed a natural circadian rhythm.

In other words, researchers found that the number of genes displaying the normal body clock were actually six times lower than expected, while manifesting themselves via disruptions of internal biological body processes. This also included receptors linked to transcription as well as translation functions.

"The results suggest that sleep-wake cycles affect molecular mechanisms which are at the core of the generation of circadian rhythms of gene transcriptions," said lead study author, Derk-Jan Dijk, via the release.

Researchers note via a study from last year that even one week of disrupted sleep can affect hundreds of genes. 

More information regarding the study can be found via the Proceedings of the National Academy of Sciences.